There’s going to be apx. 8 people. What I’m planning is to do apx. 3 1/2 - 4 racks of baby back ribs, and about 15 sausages. Getting both of these meats from a great local butcher. I’m going to be using a rub for the baby backs, and thinking of a an injector marinade for the sausages.

How much charcoal / wood do you use for the fire (I’m using hard wood lump charcoal)?
How long should I smoke these meats for? I’ve heard apx. 4 hrs. for the ribs - I’m using a rib rack, and apx. 2 hrs. for the sausages. What does everyone think? Does this sound about right?

Sounds like a great meal to me!! I usually figure half a rack per person if I'm serving with something else, a whole rack per person if they are a stand alone. You should be good with the quantity you're talking about for a group that size. To me it sounds like you're right on with everything else though. 4 Hours...yup. 2 Hours...yup. Dry rub...yup. Also try spraying with beer/vinegar or cider vinegar as they cook. I'm a sauce and rub guy so I'd go with both, you can't fail with a Jack Daniels BBQ sauce in my opinion. I've never injected (or heard of) injecting sausage. Given the fat content of sausage to begin with my thought is that it would be unnecessary. See what anyone else has to say though. I'm not going to offer any advise on the charcoal since I'm primarilly a gas man. I would suggest apple wood for smoking. Pork loves applewood. Two other pointers, if you want rib advise search the board, you'll find more than you've ever wanted to know (my Grand Feast Thread even had similar meats). Or ask Dkirn. He's my goto guy on ribs!
Good Luck and Enjoy the meal and the race!

Mmacdone..Welcome to the board. I hope that you are able to find the information you are looking for. I agree with Grand Scales advice to search the board, there's a lot here. I might also suggest, Steven Raichlen's books. They are worth the investment.

I agree with Grand Scale on the sausage- I've never heard of anyone injecting a sausage- not that it hasn't been done. The sausage is already seasoned, and the high fat content will keep them plenty juicy.
As for the ribs, you may also choose to spray the ribs with good old apple cider- many board members go with that. They will be done when the meat starts to pull back about a quarter inch from the end of the bones. As for the amount of charcoal, I would say add enough to keep the temp at a steady 220 or so (opinions may vary) measured at the food level. I know that is a vague answer but it will all depend on the weather/wind conditions, your baffle settings etc. Being that you are using natural lump, you will not need much initially to get to this temp, however natural lump will burn quicker as well as hotter so you may need to replenish more often. The good news is that you can just throw the natural lump right on the fire, no need to use a chimney starter or other method to let the coals burn down. If I am doing any extended time indirect cooking, I usually add plenty of charcoal and control the burn rate with air flow control, you'll want to limit that amount of times you open the smoker up. Cheers.

I'm only half awake, but did I just read Grand Scale recommending a store bought BBQ sauce?!

Chagan you scared me the there! I went back and re-read my post. What I reccomended was a Jack Daniels BBQ sauce. Not necessarilly the store bought variety. If memory serves there is a version in "Sauces Rubs and Marinades". There are also many others out on the net.
There is a time and a place for store bought sauce, its just not on race day with babybacks!

So I have been away from the board for a little while (my companies are very busy right now and requiring alot more of my time) but I started to worry when I thought that I read that Grand Scale was using a store bought sauce on his ribs! Thankfully he cleared that up.